The long term objectives of this research program are directed towards the synthesis of the diazonamides, and intermediates that may also exhibit cytotoxic activity. The diazonamides are cytotoxic marine natural products that have unprecedented structures unlike any other compounds. It was reported that diazonamide A has potent in vitro activity against HCT-116 human colon carcinoma and B-16 murine melanoma cancer cells (IC50 less than 15 ng/mL). Part of the synthetic studies will involve the generation of persistent radical intermediates that should add to pi-deficient heterocycles and form the key central hindered bond present in the diazonamides.